FANNIE MAE COMMITMENTS AND PLEDGED SECURITIES - Pledged Securities at Fair Value (Detail) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020
Pledged securities
Pledged securities, at fair value	$ 151,413	$ 148,996
Total pledged cash and cash equivalents
Pledged securities
Pledged securities, at fair value	12,624	44,733	$ 51,550	$ 17,473
Restricted Cash - Pledged
Pledged securities
Pledged securities, at fair value	8,454	3,779	10,596	4,954
Money Market Funds
Pledged securities
Pledged securities, at fair value	4,170	40,954	40,954	12,519
Agency MBS
Pledged securities
Pledged securities, at fair value	138,789	104,263	97,224	119,763
Asset Pledged as Collateral with Right | Pledged Securities - Fannie Mae DUS Program
Pledged securities
Pledged securities, at fair value	$ 151,413	$ 148,996	$ 148,774	$ 137,236